Study Of New Nuclei Targeted Gene Carrier

In this research, Triamcinolone acetonide was conjugated to low molecular weight polyethylenimine (PEI 1800) by one-step reaction using the Traut’s reagent. This novel polymer could complexed with pDNA to form compact particle and efficiently translocated into the nucleus.The ability of DNA binding of TA-PEI was determinatied by gel retardation assay, the TA-PEI/DNA complex was completely retarded at or above 0.5/1 weight ratio (polymer/DNA). The average size distributions of the complexes were measured at various weight ratios and were in the range around 100nm. Zeta potential of TA-PEI/DNA polyplexs remained constantly between 20mV-40 mV when the weight ratio of TA-PEI /DNA increased from 3 to 4.Cytotoxicity and transfection efficiency of the copolymers were also checked in cultured HEK293 human embryonic kidney cell line and HepG2 human hepatoblastoma cell line. Its cytotoxicity was lower than PEI 25kDa. In vitro transfection assay of TA-PEI showed the highest luciferase expression at a 3/1-4/1 weight ratio. The result showed that the TA-PEI/DNA complex had similar gene delivery efficiency compared to PEI 25kDa/DNA complex. Confocal microscopy examination confirmed that GC-PEI/DNA complexes were more effectively translocated in the nucleus than PEI 25K/DNA or PEI 1800/DNA complexes.These results demonstrated that transfection activity of TA-PEI polymer was high but its cytotoxicity was low relatively, and it could translocate into the nucleus efficiently. This novel polymer might be useful for gene therapy as promising nuclear-targeting carrier.